Knowing what type of psoriasis you have can help you and your doctor come up with an effective treatment plan.

Your physician can usually diagnose the form based on your symptoms and a careful skin examination. But a biopsy is sometimes needed for confirmation.

Because psoriasis can look like other skin conditions that cause itchy, scaly rashes with inflammation, it is often confused with various disorders. These may include common skin conditions, such as eczema, heat rash, types of skin cancers, and dandruff. Psoriasis can also resemble and be confused with the fungal infection known as ringworm.

Most people have just one kind of psoriasis, but you can develop a new type of the skin disorder at any time. (1)

What Is Plaque Psoriasis?

Plaque psoriasis, which is also called psoriasis vulgaris, is the most common type.

What Is Guttate Psoriasis?

Guttate psoriasis, from the Latin for “raindrop shaped,” causes small, dot-like spots on the body. These pinkish, red lesions frequently appear on the upper arms, trunk, thighs, or scalp.

Often, this form of psoriasis first starts in childhood or young adulthood.

Guttate psoriasis can be triggered by a strep infection, tonsillitis, stress, a skin injury, or certain medication (such as beta-blockers). Sometimes genetic factors are to blame.

This type of psoriasis may clear up without any treatment. But certain cases require medical therapy. In some patients, it's just a single episode, but in others it may signal the start of plaque psoriasis.

What Is Pustular Psoriasis?

This uncommon form of psoriasis most often affects adults.

Pustular psoriasis is characterized by pus-filled bumps (called pustules) surrounded by redness on the skin. These blisters contain white blood cells and are not infectious or contagious. (4)

The bumps may cause:

Soreness

Pain

The pustules can appear on any part of the body but most often show up on the hands or feet.

When the bumps dry out, they can leave behind brown dots or scales on the skin.

Some triggers may increase your risk of developing this form of psoriasis. These include:

Systemic steroid medication

Suddenly stopping the use of certain medication, including topical steroid medicines

Pregnancy

Infection

Stress

Too much sunlight

Certain chemicals

Occasionally, the pustules can cover the entire body, which is known as generalized pustular psoriasis, or Von Zumbusch psoriasis. This is a serious condition that requires immediate medical attention.

Symptoms of generalized pustular psoriasis include:

Fever

Nausea

Chills

Bright red skin

Fatigue

Muscle weakness

Severe itching

Loss of appetite

Fast heart rate

What Is Inverse Psoriasis?

With inverse psoriasis, people develop lesions that are bright red, smooth, and shiny.

These spots typically show up on creased areas of the body where skin meets skin, such as the underarms, behind the knees, under the breasts, near the buttocks and genitals, or on the groin.

This condition can cause sore skin, which may worsen if you sweat or rub the area.

It’s sometimes triggered by a buildup of yeast.

Some people who develop inverse psoriasis also suffer from another form of psoriasis. (5)

What Is Erythrodermic Psoriasis?

This is an uncommon but very serious form of psoriasis. Only 3 percent of people with psoriasis will develop erythrodermic psoriasis in their lifetime, according to the NPF.

This type usually occurs in people who have uncontrolled plaque psoriasis.

Erythrodermic psoriasis causes fiery-looking skin that affects most of the body. (6)

Symptoms include:

Burning

Peeling

Severe itching

Pain

Fast heart rate

Change in body temperature

If you have erythrodermic psoriasis, you’ll need immediate treatment, as it can be a life-threatening condition.

This form of psoriasis can cause complications, such as protein and fluid loss, infection, pneumonia, severe swelling, or congestive heart failure.